Abstract: A sacrificial memory opening fill structure for a multi-tier memory device may include a semiconductor fill material portion a metallic fill material portion to enhance control of a vertical cross-sectional profile of an inter-tier memory opening. Multiple inter-tier dielectric layers may be employed to reduce sharp corners in a memory opening fill structure. Alternatively or additionally, a combination of an isotropic etch process followed by an anisotropic etch process may be used to form a first-tier memory opening.

Abstract: A sacrificial memory opening fill structure for a multi-tier memory device may include a semiconductor fill material portion a metallic fill material portion to enhance control of a vertical cross-sectional profile of an inter-tier memory opening. Multiple inter-tier dielectric layers may be employed to reduce sharp corners in a memory opening fill structure. Alternatively or additionally, a combination of an isotropic etch process followed by an anisotropic etch process may be used to form a first-tier memory opening.

Abstract: Semiconductor devices laterally surrounded by at least one dielectric material portion are formed over a substrate. At least one edge seal ring structure is formed around the semiconductor devices and the at least one dielectric material portion. One or more of the at least one edge seal ring structure has a horizontal cross-sectional profile that includes laterally-extending regions that extend laterally with a uniform width between an inner sidewall and an outer sidewall, and notch regions connecting neighboring pairs of the laterally-extending regions and having a greater width than the uniform width. Cavities in the laterally-extending regions are connected to cavities in the notch regions to allow outgassing from the material of the at least one edge seal ring structure.